Improper input validation in Free5gc
CVE-2026-44325
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NRF root SBI endpoint POST /oauth2/token contains a parser-level type-confusion bug family. The handler in NFs/nrf/internal/sbi/api_accesstoken.go reflects over models.NrfAccessTokenAccessTokenReq, special-cases only plain string and NrfNfManagementNfType fields, and treats every other field as if it were a single models.PlmnId. The parsed *models.PlmnId is then assigned with reflect.Value.Set() to whichever field name the attacker put in the form body, which panics whenever the destination field's real type is incompatible (slice, different struct, primitive). Gin recovery converts each panic into HTTP 500, but the endpoint remains remotely panicable from a single unauthenticated form-encoded request and is repeatedly triggerable. This vulnerability is fixed in 4.2.2.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (49.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003
Affected products
- Free5gc — versions < 4.2.2
Weakness classification (CWE)
References
- github.com/free5gc/free5gc/security/advisories/GHSA-f8qv-7x5w-qr48 (Exploit, Vendor Advisory)
- github.com/free5gc/free5gc/issues/918 (Exploit, Issue Tracking)
- github.com/free5gc/nrf/pull/83 (Patch, Issue Tracking)
- github.com/free5gc/nrf/commit/f7bc77daa7425506af7569f2e61c2a210f5a0423 (Patch)
Frequently asked questions
- What is CVE-2026-44325?
- CVE-2026-44325 is a high-severity vulnerability in Free5gc, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-05-27.
- How severe is CVE-2026-44325?
- High severity. CVSS v3 base score is 7.5 out of 10.